<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>页面卷角</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        body {
            background: #fff;
        }

        .box {
            position: absolute;
            right: 0;/*靠右*/
            top: 0;/*靠上*/
            width: 100px;/*宽*/
            height: 70px;/*高*/
            background: linear-gradient(35deg, #EEE 40%, rgba(137, 137, 137, 1) 50%);/*35度角渐变色填充，角度根据宽高比来决定*/
            filter: drop-shadow(0px 0px 8px #1f1f1f);/*阴影*/
        }

        .box:hover {/*鼠标指向后放大*/
            width: 200px;/*宽度加倍*/
            height: 140px;/*高度加倍*/
        }
        /*虽然不是很逼真，但是代码简单，我最喜欢用最少的代码来完成想要做的事情*/
        p{
            color:blue;
            text-align: right;
            line-height: 30px;
        }
    </style>
</head>
<body>
    <h2>一收哥http://www.yishouge.co</h2>
    <div class="book">
        <div class="box">
            <p>登录</p>
        </div>
    </div>
</body>
</html>